The little black beetles you find in cricket orders are domestic beetles. They put them in there to eat the dead crickets. Harmless. Never heard of the cleaning crew thingamajig. I breed dubia roaches and have never had to use anything like that. Dubia live much longer than crickets therefore, fewer dead ones and less smell. Not really a good thing to receive an order of dubia with any kind of larvae or beetles. Dubia have kind of an "earthy" smell. As for their poo, its called frass. They give live birth and the babies will eat the frass until they are big enough to eat gut load. If kept properly, dubia are super easy to care for. I only have to clean my colonies once a month and its not that big of a deal to do so. I feed my chams these, crickets, superworms, etc.. Good to mix it up.